The major histocompatibility complex class Ib molecule HLA-E at the interface between innate and adaptive immunity

Area of Science:

• Immunology
• Molecular Biology
• Structural Biology

Background:

• Human leucocyte antigen (HLA)-E is a non-classical major histocompatibility complex (MHC) class I molecule.
• It exhibits low polymorphism compared to other MHC class I molecules.
• HLA-E serves as a ligand for receptors on both innate and adaptive immune cells.

Purpose of the Study:

• To elucidate the dual role of HLA-E in immunity.
• To understand the structural basis of HLA-E recognition by immune receptors.
• To investigate HLA-E's function in immune surveillance and adaptive responses.

Main Methods:

• X-ray crystallography to resolve HLA-E structures.
• Biochemical assays to study ligand binding.
• Cell-based assays to assess immune cell recognition.

Main Results:

• Structural resolution of HLA-E in complex with innate and adaptive ligands.
• Demonstration of HLA-E's interaction with CD94-NKG2A receptors on natural killer (NK) cells.
• Evidence for HLA-E recognition by T-cell receptors on CD8 T cells.

Conclusions:

• HLA-E plays a critical role in immune surveillance by NK cells through self-peptide recognition.
• HLA-E is involved in adaptive immune responses to pathogens via T-cell recognition.
• Structural insights reveal the molecular mechanisms underlying HLA-E's dual immune functions.